Re: Comedi & real time interrupts.

> I have read docs, but can't find really up 2 date explanations. and also
> have a quick look at some code in rt.c since comedi_request_irq looks to
> be defined there, but this seems to use request_irq, not rt_request_irq
> ????

There are a couple versions of comedi_request_irq in rt.c.  Which one ends
up being used depends on which realtime package comedi gets linked
against.

To my recollection, comedi tries to get an unshared IRQ using request_irq
before calling rt_request_irq.  This will fail if any other device is
using the same IRQ line.  If it succeeds, you'll get an entry in
/proc/interrupts for your device that always shows zero interrupts (since
the IRQ's never get to the Linux domain).

I don't know if that helps, but for what it's worth, I've been having
trouble with RTAI interrupts in a driver for some custom in-house hardware
at my employer.  Everything works fine under RTAI 3.3, but I tried
upgrading one of our computers to 3.4 and the computer hard-locks on
interrupts.  I haven't had a chance to figure out what's wrong yet...

-Tabish

Received on 2007-02-13Z16:16:45